Mucosal-Associated Invariant T (MAIT) cells are impaired in Th17 associated primary and secondary immunodeficiencies

The recently described Mucosal Associated Invariant T (MAIT) cells mediate specific recognition of bacterial and fungal vitamin B2 metabolites. As innate T cells, they possess broad effector responses, including IFN- including Iproduction, that are comparable to conventional T cell responses. Immunodeficiencies associated with systemic Th17 deficiency may also be compounded by defects in MAIT immunity. We evaluated Th17 immunity in this innate T cell compartment in primary (AD-HIES) and secondary immunodeficiency (thymoma) patients with conventional Th17 deficiency and susceptibility to fungal and bacterial disease. Our results suggest that MAIT cells are both reduced and functional deficient in STAT3 deficiency and thymoma patients with IL-12/23 autoantibodies. In contrast, thymoma patients without autoantibodies preserved the normal number and functional MAIT cells

Activated phosphoinositide 3-kinase δ syndrome: Update from the ESID Registry and comparison with other autoimmune-lymphoproliferative inborn errors of immunity

Background: Activated phosphoinositide-3-kinase d syndrome (APDS) is an inborn error of immunity (IEI) with infection susceptibility and immune dysregulation, clinically overlapping with other conditions. Management depends on disease evolution, but predictors of severe disease are lacking. Objectives: This study sought to report the extended spectrum of disease manifestations in APDS1 versus APDS2; compare these to CTLA4 deficiency, NFKB1 deficiency, and STAT3 gain of-function (GOF) disease; and identify predictors of severity in APDS. Methods: Data was collected from the ESID (European Society for Immunodeficiencies)-APDS registry and was compared with published cohorts of the other IEIs. Results: The analysis of 170 patients with APDS outlines high penetrance and early onset of APDS compared to the other IEIs. The large clinical heterogeneity even in individuals with the same PIK3CD variant E1021K illustrates how poorly the genotype predicts the disease phenotype and course. The high clinical overlap between APDS and the other investigated IEIs suggests relevant pathophysiological convergence of the affected pathways. Preferentially affected organ systems indicate specific pathophysiology: bronchiectasis is typical of APDS1; interstitial lung disease and enteropathy are more common in STAT3 GOF and CTLA4 deficiency. Endocrinopathies are most frequent in STAT3 GOF, but growth impairment is also common, particularly in APDS2. Early clinical presentation is a risk factor for severe disease in APDS. Conclusions: APDS illustrates how a single genetic variant can result in a diverse autoimmune-lymphoproliferative phenotype. Overlap with other IEIs is substantial. Some specific features distinguish APDS1 from APDS2. Early onset is a risk factor for severe disease course calling for specific treatment studies in younger patients. (J Allergy Clin Immunol 2023;152:984-96.

Association between micronutrient levels and chronic spontaneous urticaria

Previous reports have suggested a possible role for vitamin D in the etiology of chronic spontaneous urticaria (CSU); however, little information is available regarding the role of other micronutrients. We, therefore, analyzed vitamin D, vitamin B12, and ferritin levels in CSU patients (n = 282) from a preexisting database at Southampton General Hospital. Data were compared against mean micronutrient levels of the general population of the UK, obtained from the National Diet and Nutrition Survey. Vitamin D levels of CSU patients were found to be higher than those of the general UK population (P = 0.001). B12 levels were lower in patients with CSU (P < 0.001) than in the general population. Ferritin levels were found to be lower in male CSU patients than in the general male population (P = 0.009). This association between low B12 and iron levels and CSU might indicate a causal link, with micronutrient replacement as a potential therapeutic option

The activation of complement and its role in the pathogenesis of thromboembolism

It is well established that inflammation and thrombosis are intricately linked processes, and there is increasing evidence of the importance of their roles in activated complement in the pathogenesis of thromboembolism. The two systems are activated by similar stimuli simultaneously and interact, either directly or through biochemical mediators, to protect the host from microbial invasion. Diseases characterized by complement hyperactivity such as paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome have high rates of thrombosis. This review describes how disease processes where there is excessive complement activation leads to thrombosis, and the specific interactions between the complement and coagulation systems that lead to pathological thrombus formation

An observational study of the diagnosis and management of chronic urticaria in the UK

BACKGROUND: Patients with chronic urticaria (CU) in the UK could be referred to health care professionals (HCPs) with diverse specialties using different guidelines. The aims of the present study were to determine which CU guidelines HCPs in the UK use, which tests they use for the diagnosis of CU, and how they manage CU.METHODS: In this UK-wide survey, we designed a questionnaire covering the diagnosis and management of CU based on current guidelines. The link to the questionnaire was sent to the British Society for Allergy and Clinical Immunology (BSACI), the British Association of Dermatologists (BAD), the British Society of Immunology (BSI), and the Food Allergy and Intolerance Specialist Group (FAISG) of the British Dietetic Association (BDA), who distributed the link to their members.RESULTS: The questionnaire was completed by 55 allergists/immunologists, 64 dermatologists, and 43 dietitians. More dermatologists used the BAD guidelines in comparison with allergists and immunologists (93.6 vs. 12.5%; p &lt; 0.001). On the other hand, the BSACI guidelines (83.3 vs. 14.9%; p &lt; 0.001) and the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network (GA(2)LEN)/European Dermatology Forum (EDF)/World Allergy Organization (WAO) guidelines (2013) (52.1 vs. 10.6%; p &lt; 0.001) were used by more allergists and immunologists compared to dermatologists. Differences were found between allergists/immunologists and dermatologists with regard to guidelines used, investigations performed, preference of first-line antihistamine, and prescription of alternative treatment methods.CONCLUSION: In conclusion, differences in the diagnosis and management of CU between HCPs of diverse specialties were identified, which reflected differences among the guidelines used<br/

Differential Impairment of Interferon-γ Responses in Two Cases of Pulmonary Nontuberculous Mycobacterial Disease

Nontuberculous mycobacteria (NTMs) are weakly virulent intracellular pathogens that are common in food and water supplies. The persistent culture of these organisms in the setting of clinical infection warrants investigation of immune function. In cases of isolated pulmonary NTM (PNTM) disease, underlying immune defects have not been clearly identified. We present two patients with isolated PNTM infection who demonstrated differentially impaired IFN-γ production across a range of stimuli. These cases show that cellular IFN-γ responses may be defective in a proportion of patient suffering PNTM disease and that when assessing responses, the stimulant used in the testing is important to delineate defective cell populations. Impaired IFN-γ responses to IL-12 + BCG seem to be a poor prognostic indicator in PNTM disease and in these cases were not improved by adjuvant IFN-γ

Thymic epithelial cells promote survival of human T-cell acute lymphoblastic leukemia blasts: the role of interleukin-7

T-cell lymphoblastic leukemia (T-ALL) cells originate within the thymus from the clonal expansion of T cell precursors. Among thymic stromal elements, epithelial cells (TEC) are known to exert a dominant inductive role in survival and maturation of normal, immature T-cells. In this study we explored the possible effect of TEC on T-ALL cell survival and analyzed the role of interleukin-7 (IL-7) within the microenvironment generated by T-ALL-TEC interactions